Rubbing machine



Nav. i6, 1943. R. J. CHAMPAYN'E RUBBING MACHINE Filed July 28, 1941 2Sheets-Sheet l wivl.,

Nov. 16, 1943. R. 1, CHAMPAY'NE 3 2,334,172

RUBBING MACHINE Filed July 28, 1941 2 Sheets-Sheet 2 85 if 7 i 5f ,65 f49 a e3 v/es 2 9 8 Patented Nov. 16, 1943` UNITED sTATEs PATENT OFFICERUBBING MACHINE Roy J. Champayne, Rockford, Ill.

Application July 28, 1941, Serial No. 404,307

16 Claims.

This invention relates generally to portable surface finishing machinesand more particularly to power driven machines of the type in which therubbing element has a gyratory motion.

One object of the invention is to provide an improved machine of theabove character embodying novel means for imparting positive gyratorymovement to the rubbing element.

A more detailed object is to provide a flexible housing arranged in anovel manner to hold the rubbing element against rotation and alsoeffectually exclude foreign matter from the working parts.

A further object is to provide a novel means for sustaining the thruston the rubbing element.

Still another object is to provide for quick detachment andinterchanging of rubbing elements on the machine. 1

The invention also resides in novel structural arrangements whichcontribute to the ruggedness of the construction and the ease withwhichthe machine may be handled and controlled.

Other objects and advantages of the invention l will become apparentfrom the following detailed description taken in connection with theaccom- Apanying drawings, in which Figure l is a perspective view of theimproved rubbing machine.

Fig. 2 is a horizontal section taken along the line 2-2 of Fig. 1.

Fig. 3 is a diametrical section taken along the line 3-3 of Fig. 2.

Fig. 4 is a perspective viewA of the detached rubbing element.

Fig. 5 is a view similar to Fig. 3 illustrating a modification.

While the invention is susceptible of various modifications andalternative constructions, I have shown in the drawings and willfhereindescribe in detail the preferred embodiments. It is to be understood,however, that I do not intend to limit the invention by such disclosurebut aim to cover all modifications andv alternative constructionsfalling within the spirit and scope' of the invention as expressed inthe appended claims.

In the form shown in the drawings, the irnproved rubbing machinecomprises generally a hollow housing 4 enclosing a rotary motor 5 of anysuitable type -and supporting at its open end a work performing orrubbing element 6 positively driven by the motor and caused to movebodily in a circular path of small diameter. Power is supplied to themotor through a handle I rigid with the motor casing and projectinglaterally therefrom so that the tool may be grasped and heldconveniently in one hand. The handle also encloses a control device Ilby which the operation of the motor is controlled, this device having athick rounded top I0 from which depends a thinner walled skirt IIpreferably flared outwardly slightly /and formed around its lower endwith a flange I2.

To provide a mounting for the rubbing shoe 6, the lower end of the skirtis closed by a fiat plate I3 secured as by rivets I4 to a circular diskI5 having an upstanding annular L-shaped flange I6 overlying the skirtflange I2 which is thus disposed between the plate and the flange I6where it is held firmly by a. ring I1 tightened around the flange.

While the rubbing member 6 may be actuated by power from an externalsource transmitted mechanically into the housing, a self-containedsource such as the motor 5 is preferably employed. This may be anelectric motor, but as shown is actuated by pressure fluid, preferablycompressed air. It comprises a rigid annular casing I8 closed atopposite ends by upper and lower end plates I9 and 20 clamped togetherby screws 2| sov as to forma generally cylindrical chamber 22. The motorcasing is thus shorter than the housing skirt II and its upper end isreceived snugly in the closed iend of the rubber 1 housing so as to beheld frictionally against turning relative to this housing.

Disposed within the chamber 22 is a cylindrical rotor 23 of somewhatsmaller diameter than the chamber. In this instance, the rotor ismounted directly on and fastened as by a key 24 to a shaft 25, theopposite ends of which project through the inner race rings ofantifriction ball bearings 26. rIhe outer races are supported in the endplates I9 ad 20 and held in place by a plate 28 and a hardened plate 29fastened to the end plates by the screw 2 It.

The rotor 23 is concentric with the shaft 25 but the two are eccentricwith respect to the chamber 22 with one side of the rotor substantiallyin running contact with the chamber wall adjacent an air inlet port`3I'I. The rotor is formed with a series of outwardly opening radialslots 3| spaced lannularly and each supporting a vane 32 for radialprojecting into engagement with the chamber wall. During rotation. thevanes will follow the contour of the chamber, outward movement of thevanes occurring as a result of centrifugal force or by the leakage ofair inv behind the vanes. Compressed air entering through the port 30acts on the projecting portions of the vanes and thus imparts rotarymotion to the rotor. To insure initial starting, the wall of the chamberis provided with the gradually tapering air slot 33 extending from theinlet port in the directionin which the rotor turns.

' ing threads onto the reduced outer end oi a stud The exhaust air flowsout through a port 34 i in the casing I8 opening into the interior ofthe housing I I which, inturn, isyented to the atmosphere through anopening 35 through which the handle 'I extends.

Rotary power derived by the motor is applied positively to the rubbingshoe 6 to produce bodily gyratory motion of the latter about the shaft25. This is accomplished through a crank formed by a projection or pin36 on the lower end of the shaft and disposed parallel to buteccentrically of the shaft axis. The crank pin is operatively connectedto the rubbing element by antifriction bearings 3'I having their innerrace ring carried by the shaft and the outer ring abutting against theplate I3. This ring is seated in the ange 38 of an annular stamping 39secured on top of the disk I5 by the rivets I4.

Since the plate I3 is held against rotation by the housing skirt II, therubbing shoe 6 -will necessarily follow the circular path described bythe crank pin 36 when the shaft 25 is rotated, the range of movementbeing determined by the throw of the crank. Herein this is approximately13s of an inch.

Antifriction bearing means is provided for transmitting' directly to therigid motor casing the thrust incident to pressing the shoe against thesurface to be finished. This means comprises a series of steel balls 40held in an annular carrier 4| and disposed between the hardened plate 29on the lower end of the motor casing, and a ring 42 seated Within thedisk ange I6. The bearing is centered yieldably by a ring 43 of rubberor other suitable resilient material surrounding the stamping 39 andenclosed by a split ring 44. The balls 40 thus transmit the axial thrustto the mot'or casing and are` adapted to float laterally therebyavoiding any possibility of binding.

The machine is applied to the surface to be finished and manipulated bymeans of the handle 1. This comprises a hollow casting ared toward oneend to form an annular shield 45. When the tool is equipped with apressure -iiuid motor such as that illustrated, the control device 6above referred to takes the form of a valve housed within the iiaredportion of the handle.

54 integral with the motor casing. Thus, with the valve casing abuttingagainst the stud and the screw 53 tightened, the handle is attachedrigidly to the motor casing.

Preferably the air line or hose by which pres-l sure uid is supplied tothe motor is connected directly to the handle. To this end, a knobportion 55 is threaded for the reception of a connector 56 of suitableand well-known type.

As above stated, the motor is started and stopped by manipulation of thehand lever 9 which, in the present instance, is pivoted on the handleinteriorly thereof, a cross pin 51 providing the pivot. Adjacent itsfulcrum, the lever bears against the endof the valve stem and the freeend is curved upwardly through a slot 5B in the handle portion 45between the housing and the handle end so as to be disposed above thehous- 'Ihe valve illustrated comprises a hollow casing 46 having inletand outlet ports 41 and 48 between which communication is establishedand interrupted by a valve member 49 movable toward and from a seat 50.The valve member is on a stem 5I which is guided in the valve casing andis urged in the valve-closing direction by a compression spring 52.

Preferably the handle'T is fastened to the rigid motor casing throughthe intermediary of the valve casing 46. For this purpose, a headedhollow screw 53 projects through the contracted portion of the handlecasting and threads into the ing top4 I 0. Thus, the lever isconveniently accessible when the tool is operated in the most naturalmanner, that is, when the handle l is held in one hand, the lever willbe depressed and the valve opened as an incident to pressing the toolagainst the work with the other hand placed on the top I0 of thehousing. When the operating pressure is relieved, the valve will closethus stopping the motor automatically. Or, when only a light pressure isrequired, the tool may be handled in one hand, by which the controllever may also be manipulated.

The rubbing shoe 6 is mounted on the plate I3 for quick detachment so asto permit the ready interchange of shoes equipped with different kindsof abrasive papers, for example, those used for Wet or dry sanding. vInthe form illustrated, the shoe 6 comprises a rubber plate 60 havingupstanding flanges 6I and 162 at the sides and ends adapted to snuglyreceive the plate I3. The end flanges have inturned upper edges 63spaced from the top of the rubber plate to Aoverlie and bear downwardlyagainst the plate I3. These edges are cut away as indicated at 64 toprovide recesses for enabling the end flanges to be gripped and bentdownwardly to strip the end of the shoe off from the carrier plate I3and thus remove the shoe. Advantage is thus taken of the flexiblecharacter of the rubber to insure a tight friction i'lt around thecarrier and over the ends of the latter while permitting of readydetachment of the shoe from the carrier.

Abrasive or polishing material is carried on a sheet 65 detachablysecured to the under sideof the shoe 6 which may be covered with a layer66 of sponge rubber cemented to the bottom of the shoe plate 60. Themeans herein shown for clamping the abrasive sheet to the platecomprises a pair of U-shaped wires 61 with their intermediate portions68 disposed in an open ended channel 69 formed in the top portion of therubber plate 60 just below the plate I3, the wires being fastened to theplate by a rivet l0. Preferably the side walls of the channel convergetoward the center from each end. The ends 1I inlet of the valve casing.The outlet of this cas- .of eachl wire are turned inwardly and projectinto Aa tube 'I2 which is adapted to roll up and around the edge of therubber plate lili and fit into a groove 13. As an incident to this, thewire portions 68 engage the Wall 'I4 resulting in compression of therubber which thus aiords the resiliency required to hold the abrasivesheet between the rollers 'I2 and the plate 66.

Where it is desired to reduce the overall dimensions or lighten theweight, the machine construction may be modified as shown in Fig. 5.

end of the motor housing. A wire 'I9 is tightened about the bead tofasten the skirt to the cup.

, the shaft and crank bearings 2B and 21. Accordingly, these are of thethrust type as shown, the crank bearing being seated in a flanged metalcup 8l disposed in an upwardly opening recess in the shoe plate 'l5 andfastened to the latter as by rivets 82. It will thus be seen that themajor The shoe plate l is notched as indicated at length of the crank,said skirt acting tohold the shoe against rotation about its own axis.

3. In a machine of the character described, the combination of a powerdriven shaft having a portion eccentric to its axis of rotation, a workperforming member, bearing means on said member concentric with saideccentric portion and providing a positive driving connection betweenthe two operable to gyrate the member positively in an orbit determinedby the throw of the eccentric portion, and means operatively connectedto said member and acting to hold the same against rotation during itsgyration.

thrust is transmitted directly to the motor shaft and sustained by thebearings thereof. However, i

the substantial rigidity of the rubber plate T525 coacting with theski-rt H- insures the'application of substantially uniform pressure onall parts of the shoe. In addition to this function, Athe skirt servesas before to hold the shoe against turnf ing while flexing laterally topermit gyration of the shoe. i

In this modification, the handle is omitted and Wi. A rubbing machinehaving, in combination, a cup-shaped housing having an end portion offlexible material, a, power actuated rotary motor fitting in'saidhousing against the closed end. thereof and having a rigid casing and ashaft, a rubbing shoe connected to the open end of said housing, meansdriven by said shaft and gyrating said shoe, and antifriction bearingsdisposed -between said shoe and one end of said casing to sustain thelthrust incident to pressing said shoe against a work surface. 5. .Arubbing .machine having, in combination, a rigid non-rotatable casing, apower driven shaft i therein, a rubbing shoe adjacent the end of saidthe air hose is connected directly to thecasing 83T.'

of the valve 8 which casing may be cast integral as shown with the motorhousing i8. The valve is actuated by a lever 8i pivoted at 85 on thevalve casing.

It will be apparent from'the foregoingl that the improved rubbingmachine is of simple and compact construction and of light weight sothat it can be easily handled, yet r extremely rugged and capable ofwithstanding hard usage. Due to the novel manner of enclosing theworking parts, the machine may be used for-'either the-wet or dryrubbing operations. Because of the positive manner in which therubbing".v shoe is gyrated, sub'` stantial pressure mayV bef applied 'tothe work without danger of stalling the motor. Such a positive driveconnection between the rubbing y shoe and the motor shaft enables thegyroscopic action of the relatively heavy rotor turning at high speed tobe utilized in minimizing vibration of the tool incident to highV speedgyration of the rubbing shoe.

This application is a continuation in part of my/ copending applicationSerial No. 345,278, led

July 13,1940. Y

I claim as my invention;

g shaft, a positive driving connection between said shaft and shoeoperating to gyrate the shoe during rotation of the shaft, flexiblemeans connecting said casing and said shoe to hold. the shoe againstrotation during gyration thereof, and coacting bearing surfaces betweensaid shoe and casing surrounding said shaft and operating independentlyof the shaft and said flexible means to sustain the thrust incident topressing said shoe against a work surface.

6. A rubbing machine having, incombination, a rigid non-rotatablecasing, a power driven shaft therein, a rubbing shoe positively gyratedduring rotation of the shaft, a flexible connection between said casingand said shoe to hold the shoe against rotation during gyration thereof,and antifriction elements arranged between said casing and said shoe forfloating movement laterally of said shaft and operable to transmit tothe casing the thrust on the shoe.

7. A rubbing machine having, in combination, a rigid non-rotatablecasing, a power driven shaft therein, a rubbing shoe positively gyratedduring rotation of the shaft, a exible connection between said casingand said shoe to hold the shoe against rotation during gyration thereof,an

annular row of antifriction elements between said 1. In a rubbingmachine, the combination of ahousing of exible material h aving adepending skirt terminating in an'inwardly projecting annular flange, arubbingvshoe including a generally circular plate having aperipheralflange receiva rubbing shoe, an annular flexible skirt upstanding fromsaid shoe,` a rpower driven shaft within said skirt projectingtowardsaid shoe and carrying a crank, and bearing` means positivelyconnecting said crank and. said shoe and operable' during rotation ofsaid 'shaft to gyrate the shoe about the shaft axisln acrcle'determinedby the shoe and casing sustaining the thrust transmitted to said shoe bythe application of pressure to said housing, and a ring of resilientmaterial between said shaft and said elements to center the latter whilepermitting of floating of the elements laterally of said shaft 8. Arubbing machine having, in combination, a rubbing shoe, a rigid casing,a rigid power driven'vshaft journaled in said casing, a crank rigid withsaid shaft and journaled in said shoe to provide a positive drivingconnection betweenthe crank and shoe operating to gyrate the latter.about the. shaft during rotation of the latter, means for transmittingdirectly to said casing the thrust due to pressure applied to said shoe,and means connected at one end tosaid casing'. and

'at the other end to said shoe whereby to hold the latter againstrotation during its gyratory move` an annular skirt molded integral withand upstanding from said shoe having an open upper end, a motor disposedwithin said skirt and connected to the upper end thereof, said motorhaving a shaft projecting toward said shoe and carl rying a crank pin,and a bearing on said pin connected to said shoe for imparting bodilyrtary motion to the shoe and directly sustaining the end thrustresulting from pressure applied to the shoe.

10. A rubbing machine having, in combination, a rubbing shoe composed ofrubber or the like, an annular flexible skirt upstanding from said shoehaving an open upper end, a. power driven shaft, means Within said skirtrotatably supporting said shaft, a crank pin on the end of said shaft,and a bearing on said pin connected to said shoe for imparting bodilyrotary motion to the shoe and directly sustaining the end thrustresulting from pressure applied to the shoe.

11. A rubbing machine having, in combination, a housing having aflexible skirt, a rubbing shoe attached to the end of said skirt, arotary motor having a rigid casing disposed within and nonrotatablyconnected to said skirt, means actuated by the motor shaft to gyratesaid shoe positively during rotation of the shaft, said skirt having anopening in one side thereof, a handle projecting through said openingand connected rigidly within the skirt to said casing, and means withinthe handle for conducting motive power therethrough to said motor.

12. A rubbing machine having, in combination, a rubbing shoe, a rigidhousing, means holding said shoe against turning relative to the housingwhile permitting of gyration of the shoe relative to the housing, apower driven shaft journaled in said housing to turn about an axis fixedrelative thereto, said shaft having one end projecting from the housingtoward said shoe, an eccentric on said projecting end, and bearing meanscarried by said shoe and providing a journal for said eccentric wherebyto form a positive driving connection between said eccentric and saidshoe for effecting relative turning of the eccentric and shoe about anaxis which is xed relative to the shoe and thereby cause positivegyration of the shoe during rotation of said shaft.

13. A rubbing machine having, in combination, a rubbing shoe, a rigidhousing, means flexibly connecting said shoe and housing to permit ofgyration of the shoe in a circle relative to the housing, a power drivenshaft journaled in said housing to turn about an axis fixed relativethereto, said shaft having one end projecting from the housing towardsaid shoe, a crank on said projecting end, means providing a drivingconnection between said crank and said shoe for relative turning of saidcrank and shoe about an axis which is fixed relative to said shoewhereby to cause positive gyration of the shoe during rotation of saidshaft, and anti-friction means separate from said flexible means acting,when said shoe is pressed against a work surface to transmit to saidhousing the resultingthrust directed endwise of said shaft.

14. A rubbing machine having, in combination, a rubbing shoe, a support,means connecting said shoe and said support to permit of gyration of theshoe in a circle relative to the support, a rotary driving shaftjournaled in said support to turn about the axis of said gyration, andan eccentric connection between said shoe and said shaft operable totransmit the rotary motion of said shaft positively to said shoe andgyrate the shoe positively relative to said support and the shaft axisin synchronisrn with the rotation of said shaft, said connecting meansholding said shoe against'turning during its gyration.

15. A rubbing machine having, in combination, a rubbing shoe, a rigidsupport, means flexibly connecting said shoe and support to permit ofgyration of the shoe relative to the support, a power driven shaftjournaled on said support to turn about an axis fixed relative thereto,means providing a positive driving connection between said shaft andsaid shoe for relatively turning said shaft and shoe and effectingpositive gyration of the shoe during rotation of said shaft, and meansseparate from said flexible means acting, when said shoe is pressedagainst a work surface, to transmit to said support the resulting thrustdirected endwise of said shaft.

16. A rubbing machine having, in combination, a rubbing shoe, a rigidsupport, means holding said shoe against turning relative to saidsupport while permitting of relative gyration between the two, a powerdriven shaft journaled on said support to turn about an axis xedrelative thereto, means providing a positive driving connection betweensaid shaft and said shoe for effecting positive gyration of the shoerelative to the shaft during rotation of the shaft, and thrustsustaining menas associated with said connection and operable totransmit to said support through said shaft the major portion of thethrust applied to that portion of the shoe opposite said shaft when theshoe is pressed agains a work surface.

ROY J. CHAMPAYNE.

